/* =========================
   基础设置
========================= */

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-height: 100%;
  margin: 0;
}

html {
  background-color: var(--page-bg);
}

body {
  min-height: 100vh;

  color: var(--text);

  font-family:
    "Yu Mincho",
    "Hiragino Mincho ProN",
    "Noto Serif JP",
    "MS Mincho",
    "KaiTi",
    "STKaiti",
    "Microsoft YaHei",
    serif;
}

a,
button {
  font: inherit;
  -webkit-tap-highlight-color: transparent;
}

button {
  border: 0;
}


/* =========================
   页面背景
========================= */

.kana-page {
  position: relative;
  isolation: isolate;

  width: 100%;
  min-height: 100vh;

  padding:
    clamp(32px, 5vh, 58px)
    clamp(28px, 7vw, 100px)
    clamp(36px, 5vh, 64px);

  overflow-x: hidden;

  background-color: var(--page-bg);

  transform-origin: center center;
}


/* 背景层次层 */

.kana-page::before {
  content: "";

  position: absolute;
  inset: 0;

  z-index: 0;
  pointer-events: none;

  background:
    linear-gradient(
      90deg,
      var(--border) 0%,
      transparent 48%,
      transparent 100%
    ),
    linear-gradient(
      180deg,
      transparent 0%,
      transparent 55%,
      var(--border) 100%
    );
}

.kana-header,
.kana-selector,
.kana-introduction,
.kana-panel,
.kana-footer {
  position: relative;
  z-index: 2;
}


/* =========================
   页面顶部
========================= */

.kana-header {
  display: grid;

  grid-template-columns:
    clamp(120px, 12vw, 165px)
    1fr;

  align-items: start;

  width: min(100%, 1160px);
  margin: 0 auto clamp(62px, 8vh, 94px);
}


/* 返回按钮 */

.back-link {
  position: relative;
  z-index: 5;

  justify-self: start;

  padding-top: 9px;

  color: var(--text-muted);
  text-decoration: none;

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    "KaiTi",
    "STKaiti",
    "Microsoft YaHei",
    sans-serif;

  font-size: 0.76rem;
  font-weight: 500;
  letter-spacing: 0.18em;

  text-shadow:
    0 2px 8px rgba(7, 28, 47, 0.35);

  transition:
    color 0.3s ease,
    transform 0.3s ease;
}

.back-link:hover {
  color: var(--text-strong);
  transform: translateX(-5px);
}


/* 标题 */

.site-name {
  margin: 0 0 13px;

  color: var(--text-faint);

  font-size: 0.67rem;
  letter-spacing: 0.34em;

  text-shadow:
    0 2px 8px rgba(7, 28, 47, 0.28);
}

.page-heading h1 {
  margin: 0;

  color: var(--text-strong);

  font-size: clamp(4rem, 7vw, 6.8rem);
  font-weight: 400;
  line-height: 1;

  letter-spacing: 0.14em;

  text-shadow:
    0 3px 14px rgba(7, 28, 47, 0.24),
    0 10px 30px rgba(7, 28, 47, 0.12);
}

.page-description {
  margin: 24px 0 0;

  color: var(--text-muted);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    "KaiTi",
    "STKaiti",
    "Microsoft YaHei",
    sans-serif;

  font-size: 0.74rem;
  letter-spacing: 0.18em;

  text-shadow:
    0 2px 8px rgba(7, 28, 47, 0.26);
}


/* =========================
   平假名和片假名选择
========================= */

.kana-selector {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));

  width: min(100%, 1160px);
  margin: 0 auto clamp(56px, 8vh, 88px);

  border-top:
    1px solid var(--border-strong);
}

.selector-item {
  display: grid;

  grid-template-columns:
    58px
    minmax(0, 1fr)
    auto
    30px;

  align-items: center;
  gap: 20px;

  min-height: 130px;
  padding: 20px 28px 20px 18px;

  border-bottom:
    1px solid var(--border);

  color: var(--text);
  text-decoration: none;

  transition:
    background-color 0.35s ease,
    padding-left 0.35s ease;
}

.selector-item:first-child {
  border-right:
    1px solid var(--border);
}

.selector-item:hover,
.selector-item.is-active {
  padding-left: 28px;

  background-color:
    var(--border);
}


/* 编号 */

.selector-number {
  color: var(--text-muted);

  font-family:
    "Trebuchet MS",
    "Arial Rounded MT Bold",
    Arial,
    sans-serif;

  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.12em;
}


/* 标题 */

.selector-text {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.selector-title {
  color: var(--text-strong);

  font-size: clamp(1.9rem, 3vw, 2.9rem);
  font-weight: 400;
  letter-spacing: 0.12em;

  text-shadow:
    0 3px 12px rgba(7, 28, 47, 0.22);
}

.selector-description {
  color: var(--text-muted);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    "KaiTi",
    "STKaiti",
    "Microsoft YaHei",
    sans-serif;

  font-size: 0.68rem;
  letter-spacing: 0.14em;
}


/* 示例假名 */

.selector-example {
  color: var(--text-faint);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    sans-serif;

  font-size: clamp(3rem, 5vw, 5rem);
  font-weight: 500;
  line-height: 1;

  text-shadow:
    0 6px 20px rgba(7, 28, 47, 0.18);

  transition:
    color 0.3s ease,
    transform 0.3s ease;
}

.selector-item:hover .selector-example,
.selector-item.is-active .selector-example {
  color: var(--text-strong);
  transform: translateY(-4px);
}


/* 箭头 */

.selector-arrow {
  justify-self: end;

  color: var(--text-faint);

  font-family:
    Arial,
    sans-serif;

  font-size: 1.2rem;

  transition:
    color 0.3s ease,
    transform 0.3s ease;
}

.selector-item:hover .selector-arrow,
.selector-item.is-active .selector-arrow {
  color: var(--text-strong);
  transform: translateX(5px);
}


/* =========================
   初始提示
========================= */

.kana-introduction {
  display: grid;

  grid-template-columns:
    minmax(190px, 0.65fr)
    minmax(280px, 1fr);

  align-items: center;
  gap: clamp(40px, 8vw, 120px);

  width: min(100%, 980px);
  min-height: 290px;

  margin: 0 auto;
  padding: 38px 54px;

  border-top:
    1px solid var(--border);

  border-bottom:
    1px solid var(--border);
}

.intro-decoration {
  justify-self: center;

  color: var(--text-faint);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    sans-serif;

  font-size: clamp(8rem, 14vw, 13rem);
  font-weight: 500;
  line-height: 1;

  transform: rotate(-8deg);

  text-shadow:
    0 8px 30px rgba(7, 28, 47, 0.16);
}

.intro-label,
.panel-label {
  margin: 0 0 14px;

  color: var(--text-faint);

  font-family:
    "Trebuchet MS",
    Arial,
    sans-serif;

  font-size: 0.66rem;
  letter-spacing: 0.32em;
}

.intro-text h2 {
  margin: 0;

  color: var(--text-strong);

  font-size: clamp(1.8rem, 3.2vw, 3rem);
  font-weight: 400;
  letter-spacing: 0.09em;
  line-height: 1.5;
}

.intro-text > p:last-child {
  margin: 22px 0 0;

  color: var(--text-muted);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    "KaiTi",
    "STKaiti",
    "Microsoft YaHei",
    sans-serif;

  font-size: 0.72rem;
  letter-spacing: 0.14em;
}


/* =========================
   五十音内容区域
========================= */

.kana-panel {
  width: min(100%, 1160px);
  margin: 0 auto;

  animation: panelFadeIn 0.55s ease both;
}


/* 内容标题 */

.panel-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 30px;

  margin-bottom: 34px;
  padding-bottom: 30px;

  border-bottom:
    1px solid var(--border);
}

.panel-header h2 {
  margin: 0;

  color: var(--text-strong);

  font-size: clamp(3rem, 6vw, 5.6rem);
  font-weight: 400;
  line-height: 1;
  letter-spacing: 0.13em;

  text-shadow:
    0 5px 18px rgba(7, 28, 47, 0.24);
}

.panel-description {
  margin: 18px 0 0;

  color: var(--text-muted);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    "KaiTi",
    "STKaiti",
    "Microsoft YaHei",
    sans-serif;

  font-size: 0.7rem;
  letter-spacing: 0.15em;
}


/* 重新选择按钮 */

.close-panel {
  padding: 12px 3px;

  background: transparent;

  color: var(--text-faint);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    "KaiTi",
    "STKaiti",
    "Microsoft YaHei",
    sans-serif;

  font-size: 0.7rem;
  letter-spacing: 0.15em;

  border-bottom:
    1px solid var(--border-strong);

  cursor: pointer;

  transition:
    color 0.3s ease,
    border-color 0.3s ease,
    transform 0.3s ease;
}

.close-panel:hover {
  color: var(--text-strong);

  border-color:
    var(--border-strong);

  transform: translateY(-3px);
}


/* =========================
   五十音表格
========================= */

.kana-table {
  width: 100%;

  border-top:
    1px solid var(--border);
}

.kana-row {
  display: grid;

  grid-template-columns:
    minmax(68px, 0.7fr)
    repeat(5, minmax(84px, 1fr));

  min-height: 112px;

  border-bottom:
    1px solid var(--border);
}


/* 行名称 */

.row-name {
  display: flex;
  align-items: center;

  padding: 18px 14px;

  color: var(--text-faint);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    sans-serif;

  font-size: 0.68rem;
  letter-spacing: 0.12em;

  border-right:
    1px solid var(--border);
}


/* 单个假名 */

.kana-cell {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;

  min-width: 0;
  padding: 13px 8px;

  border-right:
    1px solid var(--border);

  transition:
    background-color 0.3s ease;
}

.kana-cell:last-child {
  border-right: 0;
}

.kana-cell:not(.kana-empty):hover {
  background-color:
    var(--border);
}

.kana-character {
  color: var(--text-strong);

  font-family:
    "Hiragino Maru Gothic ProN",
    "Yu Gothic",
    "Meiryo",
    sans-serif;

  font-size: clamp(2.6rem, 4.5vw, 4.4rem);
  font-weight: 500;
  line-height: 1;

  text-shadow:
    0 4px 14px rgba(7, 28, 47, 0.22);

  transition:
    color 0.3s ease,
    transform 0.3s ease;
}

.kana-cell:not(.kana-empty):hover .kana-character {
  color: var(--text-strong);
  transform: translateY(-4px);
}

.kana-romaji {
  margin-top: 12px;

  color: var(--text-faint);

  font-family:
    "Trebuchet MS",
    Arial,
    sans-serif;

  font-size: 0.62rem;
  letter-spacing: 0.16em;
  text-transform: lowercase;
}

.kana-empty {
  background:
    linear-gradient(
      135deg,
      transparent 0%,
      var(--border) 100%
    );
}


/* =========================
   像素小猫
========================= */

.kana-cell--cat {
  position: relative;
}

.pixel-cat {
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);

  image-rendering: pixelated;

  filter:
    drop-shadow(0 1px 2px rgba(0, 0, 0, 0.12));

  animation: catPeek 2.6s ease-in-out infinite;
  transform-origin: center bottom;
}


/* 小猫探头动画 */

@keyframes catPeek {
  0%,
  100% {
    transform:
      translateX(-50%)
      translateY(0);
  }

  12% {
    transform:
      translateX(-50%)
      translateY(-6px);
  }

  24% {
    transform:
      translateX(-50%)
      translateY(0);
  }

  50% {
    transform:
      translateX(-50%)
      translateY(0);
  }

  62% {
    transform:
      translateX(-50%)
      translateY(-5px);
  }

  74% {
    transform:
      translateX(-50%)
      translateY(0);
  }
}

.kana-final-row {
  grid-template-columns:
    minmax(68px, 0.7fr)
    minmax(84px, 1fr)
    repeat(4, minmax(84px, 1fr));
}

.kana-final-row::after {
  content: "";

  grid-column: 3 / 7;
}


/* =========================
   页面底部
========================= */

.kana-footer {
  width: min(100%, 1160px);
  margin: clamp(58px, 8vh, 94px) auto 0;
}

.kana-footer p {
  margin: 0;

  color: var(--text-muted);

  font-size: 0.68rem;
  letter-spacing: 0.2em;

  text-shadow:
    0 2px 8px rgba(7, 28, 47, 0.26);
}


/* =========================
   动画
========================= */

@keyframes panelFadeIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}


/* =========================
   中等尺寸电脑
========================= */

@media (max-width: 1050px) {
  .selector-item {
    grid-template-columns:
      48px
      minmax(0, 1fr)
      auto
      25px;

    gap: 14px;

    padding-right: 18px;
  }

  .kana-row {
    grid-template-columns:
      70px
      repeat(5, minmax(70px, 1fr));
  }

  .kana-final-row {
    grid-template-columns:
      70px
      minmax(70px, 1fr)
      repeat(4, minmax(70px, 1fr));
  }
}


/* =========================
   平板
========================= */

@media (max-width: 800px) {
  .kana-page {
    padding-right: 6vw;
    padding-left: 6vw;

    background-attachment: scroll;
  }

  .kana-header {
    grid-template-columns:
      105px
      1fr;

    margin-bottom: 58px;
  }

  .kana-selector {
    grid-template-columns: 1fr;
  }

  .selector-item:first-child {
    border-right: 0;
  }

  .kana-introduction {
    grid-template-columns:
      minmax(120px, 0.5fr)
      minmax(220px, 1fr);

    gap: 30px;

    padding-right: 30px;
    padding-left: 30px;
  }

  .kana-table {
    overflow-x: auto;
  }

  .kana-row {
    min-width: 650px;
  }
}


/* =========================
   手机
========================= */

@media (max-width: 600px) {
  .kana-page {
    padding:
      23px
      6vw
      48px;

    background-position: 58% center;
  }


  /* 页面顶部 */

  .kana-header {
    display: block;

    width: 100%;
    margin-bottom: 48px;
  }

  .back-link {
    display: inline-block;
    margin-bottom: 31px;
  }

  .page-heading {
    padding-left: 3vw;
  }

  .page-heading h1 {
    font-size: clamp(3.6rem, 17vw, 5.3rem);
    letter-spacing: 0.08em;
  }


  /* 分类 */

  .kana-selector {
    margin-bottom: 48px;
  }

  .selector-item {
    grid-template-columns:
      38px
      minmax(0, 1fr)
      auto
      20px;

    min-height: 112px;
    padding: 17px 8px;

    gap: 10px;
  }

  .selector-item:hover,
  .selector-item.is-active {
    padding-left: 14px;
  }

  .selector-title {
    font-size: clamp(1.5rem, 8vw, 2.1rem);
  }

  .selector-example {
    font-size: clamp(2.6rem, 13vw, 4rem);
  }


  /* 初始提示 */

  .kana-introduction {
    display: block;

    min-height: 0;
    padding: 40px 12px;
  }

  .intro-decoration {
    margin-bottom: 32px;

    font-size: clamp(7rem, 35vw, 10rem);
  }

  .intro-text {
    text-align: center;
  }

  .intro-text h2 {
    font-size: clamp(1.45rem, 7vw, 2.2rem);
  }


  /* 内容标题 */

  .panel-header {
    display: block;
  }

  .panel-header h2 {
    font-size: clamp(3rem, 15vw, 4.6rem);
  }

  .close-panel {
    margin-top: 28px;
  }


  /* 手机上每行保持横向排列，可左右滑动 */

  .kana-table {
    overflow-x: auto;

    scrollbar-width: thin;
    scrollbar-color:
      var(--border-strong)
      var(--border);
  }

  .kana-row {
    grid-template-columns:
      58px
      repeat(5, 74px);

    min-width: 428px;
    min-height: 94px;
  }

  .kana-final-row {
    grid-template-columns:
      58px
      74px
      repeat(4, 74px);
  }

  .row-name {
    padding-right: 8px;
    padding-left: 8px;

    font-size: 0.6rem;
  }

  .kana-character {
    font-size: 2.7rem;
  }

  .kana-romaji {
    margin-top: 9px;
    font-size: 0.56rem;
  }
}


/* =========================
   减少动态效果
========================= */

@media (prefers-reduced-motion: reduce) {
  .kana-page,
  .kana-panel {
    animation: none;
  }

  .back-link,
  .selector-item,
  .selector-example,
  .selector-arrow,
  .close-panel,
  .kana-cell,
  .kana-character {
    transition: none;
  }
}